This invention relates to a circuit arrangement for the selection of one among a plurality of radioelectric signals receivable in a signal receiving set, particularly television signals, comprising a memory circuit in which information relating to a plurality of tunable signals can be stored in digital form. A circuit arrangement of this type is described in copending U.S. patent application Ser. No. 729,757 filed on Oct. 5, 1976 in the name of Mario Malerba and of common assignment herewith.
Such circuit arrangement, applied, for example, to a television set, comprises a voltage controlled oscillator (VCO) whose output signal has a frequency determined by a control loop as a function of a number N different for each one of the frequencies of the selectable signals and obtained from a memory circuit. To select a frequency of a television channel, the number of the channel is set, for example, by means of a push button panel having ten push buttons numbered from 0 to 9, as that of a pocket calculator, and is sent as an address to the memory circuit which substantially produces the number N corresponding to the frequency to be selected. In this way, it is possible to select directly any one of 100 tunable channels, by forming a number of two figures from 00 to 99 on the push button panel. Moreover, it is possible to apply to the tuning thus obtained, which is the theoretical tuning, a manual correction by means of two further push buttons, which determines a variation of the less significant digits of the number N. Thus, it is possible to store in one of the cells of a second memory circuit the information for forming the number N, which is relative to the tuned channel, and to correlate it to a chosen one of the ten push buttons of the panel, so that it will then be possible to read out the ten stored channels with the tunings already corrected.